546 Intelligence and Miscellaneous Articles, 



Styria, and referred briefly to the researches of Prof. Reuss and 

 Prof. Stur upon them. He then indicated certain species of fossils 

 which he had detected in these beds, adding about nine species to 

 Stur's list. 



LXXIII. Intelligence and Miscellaneous Articles. 



ON THE COSMIC DUST WHICH FALLS ON THE SURFACE OF THE 

 EARTH WITH THE ATMOSPHERIC PRECIPITATION. BY A. 

 E. NORDENSKIOLD*. 



C\N the occasion of an extraordinary fall of snow, which took 

 ^ place at Stockholm in the first days of December 1871, M. 

 Nordenskiold was curious to ascertain if the snow, though apparently 

 pure, did not contain solid particles involved in its fall. When snow 

 had already been falling for several days, and must therefore have 

 removed from the atmosphere the greater part of the impurities 

 which it might contain, he collected upon a sheet a cubic metre of 

 fresh snow, which left on fusion a small solid residue. This con- 

 sisted of a black powder resembling coal. Heated, it gave liquid pro- 

 ducts of distillation ; calcined, it was reduced to a brown-red ash. 

 Moreover it contained a number of metallic particles attracted by the 

 magnet and giving all the reactions of iron. 



The experiment having been made in the vicinity of a large city, 

 was not sufficiently conclusive ; and it was important to repeat it 

 under other conditions, at a distance from every human habitation 

 and industry. This was done by Professer Nordenskiold in the 

 Swedish polar expedition in 1872, which was detained by the ice 

 as early as the commencement of August in about the 80th de- 

 gree of north latitude, before reaching Parry's Island to the north- 

 west of Spitzbergen, where it was to winter. 



The exam ination of the snow which covered the icebergs, having 

 evidently come from still higher latitudes, showed that it was strewn 

 with a multitude of minute black particles, spread over the surface 

 or situated at the bottom of little pits, of which the upper layer of 

 snow presented a great quantity, or, again, lodged in the lower strata. 

 This powder, which became grey on drying, included a large pro- 

 portion of metallic particles attracted by the magnet, and became 

 coated with copper by immersion in sulphate of copper. 



An observation made a little later upon other icebergs proved the 

 presence of a powder absolutely identical, in a layer of granular 

 crystalline snow situated at some centimetres depth beneath a layer 

 of light fresh snow and a second layer of hardened snow. 



In the course of the expedition the author was able to collect 

 several milligrammes of this substance, which on chemical analysis 

 was found to contain metallic iron, phosphorus, cobalt, and probably 

 nickel, with a residue insoluble in chlorhydric acid, and containing, 

 among other things, fragments of Diatomacese. 



The powder thus collected on the polar sea to the north of Spitz- 



* Poggendorff's Annalcn, 18/4, vol. cli. p. 154. 



